This invention is directed to a manual control mechanism for an electronic wristwatch, and, in particular, to a manual control mechanism that permits a plurality of signals produced by the timekeeping circuitry of an electronic wristwatch to be selectively utilized for a particular purpose such as keeping time or detecting the rate of timekeeping being performed thereby.
One approach that has been adopted for substantially reducing the current consumption of analog display electronic wristwatches is the elimination of the second hand. Specifically, in analog display electronic wristwatches, the clock hands are incrementally advanced in response to the incremental rotation of a step motor. Accordingly, if the second hand is eliminated, the time period of the low frequency timekeeping signal applied to the step motor can be increased considerably, thereby reducing the amount of current required to drive the step motor. For example, the step motor of an electronic wristwatch that is devoid of a second hand can be driven by a low frequency timekeeping signal having a period of ten seconds or more.
Although the increase in the period of the low frequency timekeeping signal considerably reduces the current consumption of the electronic wristwatch and, hence, increases the life of the battery utilized to energize same, timing rate detection is clearly rendered more difficult as a result thereof. Specifically, in order to adjust the timekeeping circuitry of an electronic wristwatch, rate detection circuitry is utilized to detect the timing rate of the timekeeping circuit. It is noted, however, that if the period of the low frequency timekeeping signal is on the order of ten seconds or more, the time required for the detection circuit to accurately determine the timing rate of the timepiece is also considerably increased. Alternatively, if the time for servicing the wristwatch is not considerably increased, the accuracy with which the timing rate is corrected is considerably lessened. Accordingly, an electronic wristwatch control mechanism that eliminates the disadvantages noted above of providing a low frequency timekeeping signal having a period of more than one second is provided by the instant invention.